desktop background on my imac but want to use a few pictures of cars

Hi all, yes another question for you all. I want to change my desktop background on my imac but want to use a few pictures of cars(maybe 20 in total) to create the new background. HELP NEEDED PLEASE. ;D ;D

do you want to create one picture with 20 cars, or get the desktop to change picture every now and again?

Place your photos/downloads into iPhoto, go to Systems Preferences > Desktop and select iPhoto and up they will come. Just click on your choice.

many thanks for the replies im looking for one picture to include the 20 cars, but the idea of it changing picture every now and then sounds good as well.like this
http://img.photobucket.com/albums/v421/slappythehomelessclown/wheels/finalversion.jpg